diff --git a/policycoreutils/audit2allow/audit2allow b/policycoreutils/audit2allow/audit2allow
index ffc1f4c9..e9c80f0d 100644
--- a/policycoreutils/audit2allow/audit2allow
+++ b/policycoreutils/audit2allow/audit2allow
@@ -104,7 +104,7 @@ class AuditToPolicy:
         if name:
             options.requires = True
             if not module.is_valid_name(name):
-                sys.stderr.write("only letters and numbers allowed in module names\n")
+                sys.stderr.write('error: module names must begin with a letter, optionally followed by letters, numbers, "-", "_", "."\n')
                 sys.exit(2)
 
         # Make -M and -o conflict
diff --git a/sepolgen/src/sepolgen/module.py b/sepolgen/src/sepolgen/module.py
index edd24c6d..5818cecb 100644
--- a/sepolgen/src/sepolgen/module.py
+++ b/sepolgen/src/sepolgen/module.py
@@ -37,8 +37,8 @@ import shutil
 def is_valid_name(modname):
     """Check that a module name is valid.
     """
-    m = re.findall("[^a-zA-Z0-9]", modname)
-    if len(m) == 0:
+    m = re.findall("[^a-zA-Z0-9_\-\.]", modname)
+    if len(m) == 0 and modname[0].isalpha():
         return True
     else:
         return False